Somniosus (Rhinoscymnus) cheni sp. nov., A New Species of Sleeper Shark (Squaliformes: Somniosidae) from Eastern Taiwan, with Aspects of Embryo Biology

This paper described a new species of sleeper shark. One pregnant female with 33 embryos belonging to small-sized group of sleeper sharks caught off Hualien, eastern Taiwan in 2017. The specimen could be distinguished from other sleeper sharks of genus Somniosus in having a smaller second dorsal fin, smaller eyes, more rows of teeth in the upper jaw and fewer in the lower jaw, and a different body proportion. It’s the sixth sleeper shark species and the second small-sized species in Asia.

From the section ‘MATERIALS AND METHODS’, two main parts are pointed out that how to identify a new shark species: morphometric measurements and meristic character counts, and the paper also used statistic test to distinguish other sleeper shark species. In addition, the biological information of embryos were provided.

Please use the question below to help you understand： -Please adduce at least 5 meristic characters that can be used to identify elasmobranchs. -How to distinguish between large-sized and small-sized sleeper sharks?